Hey guys i was watching a video on The great barrier reef, They mentioned in the video of the calcium carbonate for corals, Then they mentioned that they calcium carbonate they use is the same exact thing classroom chalk is made of. I searched the internet looking for articles that may contain information on using this in a reef tank, i found one college student who had experimented with it after researching but it never mentioned the results of his experiment.

melosu58

02-04-2010 11:28 AM

I`ve never heard that but I`d be interested from others if they have.

ccCapt

02-04-2010 11:48 AM

Hard corals don't "use" calcium carbonate, it's what they are made of. They extract calcium chloride, sodium carbonate, magnesium, etc from the water and excrete it as calcium carbonate...which is their hard skeleton.

Chalk is mostly calcium carbonate with some silt, clay and silica. It has no use in a reef tank. Calcium carbonate will not dissolve is saltwater unless the pH is around 7. It would dissolve in a calcium reactor, but it probably has too many impurities to be safe to use.

divedeep1689

02-04-2010 12:10 PM

well thats interesting.

cmor1701d

02-05-2010 09:16 AM

Once again Larry is a fountain of knowledge.

catmel

02-07-2010 11:48 AM

Interesting. I would have never thought about that. You certainly dont want extra silica in your aquarium.

cmor1701d

02-07-2010 04:13 PM

Quote:

Originally Posted by catmel
(Post 1073363)

Interesting. I would have never thought about that. You certainly dont want extra silica in your aquarium.

Why not? Silica sand is just fine for an aquarium. It's not as good as the rounder, smoother edege aragonite, but it works.